Apparatus for electric welding



, M y 1941- I F. SC'JNNICHSEN 2,240,896

APPARATUS FOR ELECTRIC WELDING Filed Nov. 20, 1939 2 Sheets-Sheet l May6, 1941. F. SONNICHSEN APPARATUS FOR ELECTRIC WELDING 2 Shee ts-Sheet 2Filed Nov. 20, 1959 Patented May 6, 19.41

. 2,240,896 APPARATUS FOR ELECTRIC WELDING Francis Siinnichsem Oslo,Norway Application November 20, 1939, Serial No. 305,385 In NorwayOctober 10.1939

means of the screw bolt 8 encompass substantially 2 Claims.

The present invention relates to apparatus for electric welding of alongitudinal seam on a pipe, tube or similar body..

A main object of the invention is to provide welding apparatus, by theuse of which it is easily possible to vary the intensity of thecurrentwhich passes through the pipe or the like to be welded, therebycontrolling the heat developed in the weld.

Another object of the invention is to provide a welding apparatus inwhich electrodes of differ-' ent sizes may be used and in which exchangeof the electrodes is easily possible. A further object of the inventionis to facilitate controlling of the transition resistance between theelectrodes and the pipe or the like by varying the pressure of theelectrode on the pipe. A further object is to provide welding apparatusby which the relative position of the electrode and the seam to beWelded may be easily adjusted. v

A still further object is to make it possible to press the pipeor thelike together, more or less, without altering the position of the piperelatively to the electrode.

The invention will now be described with reference to the accompanyingdrawings in which:

Fig. 1 is a side view of apparatus according to the invention,comprising two electrode supports and Fig. 2 is an end view, partly insection, of one of the supports shown in Fig. 1.

The apparatus according to the invention'comprises two or more supportsA and B, slidably carried on a girder C. Each support includesva baseplate l resting directly on the girder C. A body 2 is by means of screwsrigidly secured to the base plate, but electrically isolated from thesame by means'of insulating material 3. The body 2 is at its topprovided with a slot 4 extending in horizontal direction transversely ofthe longitudinal direction of the girder C. Two blocks 5 are slidablymounted 'in the said slot, each block being provided with a verticalupwardly projecting pin -6 on which may be rotatably mounted a groovedroller I. The blocks 5 may be adjusted relatively to each other by meansof a threaded bolt 8 provided with right and left threads correspondingto threaded bores 9 in the blocks. A hand wheel or handle l0 mounted onthe outwardly projecting end of thesaid bolt serves for operating thebolt. l I designates a pipe to be welded along the seam l2, the pipebeing held in desired position by means of the rollers I. The grooves inthe rollers are so shaped and dimensioned that the rollers, when movedinto engagement with the' pipe by rollers .l

the whole section of the pipe, with the exception of the seam borders ontop of the pipe section and a corresponding part on the bottom side.

In order to make it possible to weld pipes of din'erent diameters therollers may be exchangeably mounted on the blocks 5, or the blocks maythemselves be ex-changeably mounted in the slot 4.

The electric current is fed to theseam l2 by meansoi a contact roller orelectrode l3. This electrodeis rigidly mounted on one end of ahorizontal shaft l4 rotatably mounted at the lower end of a guidingpiece l5. The other end of the said shaft carries contact discs l6projecting down into a quantity of mercury contained in a cup shapedcontainer ll, which by means of conduits 18 may be connected to asuitable source of electric current.

The guiding piece 15 is by means of a link l9 suspended on a lever 20pivotally mounted at 2| on a frame part 22. A spring 23 presses thelever 20 downwardly. Weights may also be hung on the vfree end of thelever in order to increase the downward pressure on the guiding piece .I5. The frame part 22 carries ball bearings or the like 24, two or moreon each side of the guiding piece l5, by means of which ball bearingsthe guiding piece is secured against movement in horizontal direction'.-The frame part 22 is rigidly secured to another frame part 25, thesetwo irame parts constituting the upper part of the support A, the lowerpart consisting substantially of base plate I, and body 2.. The framepart 25 is provided with a bracket26 on which the mercury container i'iis mounted,

As Will be understood,- the electrode or contact roller I3 is sopositioned that its rim 21 will roll against the seam oi the-pipe,between the two By means of the guiding device comprising the guidingpiece l5 and the ball bearings 24 the contact r ller is secured againstdisplacement in a direction transversely or'longitudinally of the seam.

Further an adjustable pressure between "-the contact roller and the seamis attained by means of the lever 20, spring 23 and weights being on thefree end of the saidlever.

.In order to make itpossible to use contact rollers of difierent size,the upper part of the support, comprising the frame parts 22 and 25 ismounted adjustably in a vertical direction relaspindle 29 rotatablymounted on the body I, but

electrically isolated from the same. The spindle is at its lower endprovided with a worm wheel 30 cooperating with a worm 3| rigidly mountedat the right end of a shaft 32 which may be rotated by means of the handwheel 33.

When using the apparatus according to the invention two or more supportsare mounted on a common girder and a pipe or the like to be welded isarranged in position between the rollers I. The rollers, being chosen inaccordance with the diameter of the pipe are pressed into engagementwith the pipe, if necessary with a pressure sufiicient to press theedges of the seam into contact with each other. The distance between twosupports is chosen in accordance with the strength of the current to beused and the dimensions of the pipe in such a way that a maximumoperation speed may be obtained. During the welding operation the pipeis fed through the apparatus with constant or varying speed.

I claim:

1. Apparatus for electric welding of a longitudinal seam of a. pipecomprising, a girder, a plurality of supports slidably mounted on saidgirder, means for insulating said supports with respect to the girder,two rollers rotatably mounted on each support and being adapted to bearagainst opposite sides of the pipe to be welded, a guiding piecesuspended on each support, rotatable guide means mounted on each supportfor preventing lateral movements of the guide piece in directionstransversely of the seam of the pipe to be welded, a contact rolleradapted to engage the pipe adjacent said seam rotatably mounted on eachguide piece, means for yieldably urging each guide piece toward the pipeso that each contact roller presses against the pipe adjacent the seamto be welded, and means including a conducting liquid for connectingeach contact roller to a source of current.

2. Apparatus for electric welding of a longitudinal seam of a pipecomprising, a girder, a plurality of supports slidably mounted on saidgirder, means for insulating said supports with respect to the girder,two rollers rotatably mounted on each support and being adapted to bearagainst opposite sides of the pipe to be welded, a lever pivotallymounted on each support, a guide piece suspended on each lever,rotatable guide means mounted on each support for preventing lateralmovementsof the guide piece in directions transversely of the seam ofthe pipe to be welded, a contact roller adapted to engage the pipeadjacent said seam rotatably mounted on each guide piece, means foryieldably urging each guide piece toward the pipe so that each contactroller presses against the pipe adjacent the seam to be welded, andmeans including a conducting liquid for connecting each contact rollerto a source of current.

F. S'C'JNNICHSEN.

